After three months, during which the Bounty underwent repairs, maintenance and conversion of some of its operating systems, Kirk and his crew used the ship to return to Earth in order to face charges regarding their unauthorized appropriation of the Enterprise. During their journey home, however, they were made aware of the destructive effects on Earth of an extremely powerful alien probe. Upon further investigation, Spock realized that the probe was attempting to establish communication with humpback whales, a species which had been extinct for two hundred years. Having no choice, the crew elected to undertake the extremely risky slingshot effect to travel back in time and retrieve two humpbacks, with the intention of returning to the 23rd century and appeasing the probe.

The Bounty decloaks over a whaling ship

After successfully using a time warp to travel to the year 1986, Kirk ordered the Bounty set down in Golden Gate Park under cloak. Although it initially appeared as if the crew would be unable to return to their own time due the decrystalization of the ship's dilithium as a result of the time travel, Spock was able to develop a plan whereby high-energy photons could be collected from the nuclear reactor of a naval vessel, and then injected into the dilithium chamber, causing recrystalization. As this was occurring, CaptainScott performed a series of modifications to the Bounty's cargo bay, transforming it into a whale tank with which to transport the humpbacks. The modifications complete, the Bounty departed to retrieve the whales, in the process coming across a Finnish whaling vessel attempting to kill the whales. Still under cloak, the crew positioned the Bounty between the boat and the whales, successfully deflecting the harpoon. Kirk then ordered the Bounty decloaked, an act which had the effect of frightening the whalers off.

The Enterprise crew evacuates the Bounty

Using the Bounty's transporters, the whales were beamed aboard, and the crew was able to recreate the time warp and return to the 23rd century. However, upon their arrival, the Bounty's power systems began to fail as a result of their close proximity to the probe, and subsequently crashed into San Francisco Bay. As there was no power left with which to open the bay doors, the whales were trapped and in danger of drowning, necessitating Kirk swimming underwater and accessing the explosive override, opening the doors and freeing the whales. (Star Trek IV: The Voyage Home)

In Star Trek IV: The Voyage Home, the design of the bridge aboard the Bounty was completely redressed from the vessel's original appearance in Star Trek III: The Search for Spock. This appearance acted as a reference for all future bridges aboard Klingon ships.
An early storyboard draft of Star Trek VI: The Undiscovered Country featured the Bounty in spacedock being disassembled by Starfleetengineers.

A blocking model of the Bird-of-Prey was created by ILM. It measures approximately 9" × 2", 5" × 5", 7" × 7" and was made from foam core, cardstock, styrene, and plastic. [1]